Method and apparatus for constructing concrete piles



S. M. COTTEN. METHOD AND APPARATUS FOR CONSTRUCTING CONCRETE PILES.

APPLICATION FILED SEPT. 6. 1.918.

1,342,424. 4 PatentedJune 8,1920.

2 SHEETS-SHEET l- A TTORNEYS WIT/V588." \1 i2 mo z 'a a.

' s. M. comm. 7 METHOD AND APPARATUS FOR CONSTRUCTING CONCRETE FILES. APPLICATION FILED SEPT.6, I918.-

1,342,4:24. Patented June 8, 1920.

2 SHEETS-SHEET 2- w/mss A I/WENTOR J. A? 12 6. Gaffe?! ATTORNEYS v SHEPARD 'M. COTTEN,' 0F PHOENIX, ARIZONA.

Specification of Letters Patent. I

Faten'ted June 8, 1924).

Application filed September 6, 1918. Serial No. 252,947.

To all whom it may concern:

Be it known that I, SHEPARD M. Corr'rnn, a citizen of the United States, and a resident of Phoenix, in the county of Maricopa and State of Arizona, have invented certain new and useful Improvements in Methods and Apparatus for Constructing Concrete Piles, of which the following is a specification.

My invention is a new and improved method and apparatus for constructing cast-in-place concrete piles. The main object of this invention is to provide a method of driving and casing the hole in the ground (into which the concrete-pile is cast) so as to develop a minimum of resistance to penetration upon the part of the material penetrated. This object is accomplished by the use of a casing, consisting of a series of telescoping cylindrical sections of suitable length, which are so designed,

related, and actuated that skin-friction between the casing and the ground penetrated is practically eliminated. At any time during the process of driving the hole, the maximum possible skin-friction which can exist, will be that developed by a single section, as at any time, only one section is both in motion and in contact with the material penetrated. The hole into which the casing is placed, is formed bydriving into the ground, a drive-shaft fitted with a pointed shoe or tip, this shaft being concentric with the casing, and actuating the movements of the casing sections. The arrangement is such that the drive-shaft may be easily removed to permit the cased hole to be filled with concrete. Also, provision is made such that the shoe may be locked to the driveshaft, and these, together with the casings, withdrawn.

In the drawings:

Figure 1 is a vertical section through the apparatus in position to drive the pile,

Fig. 2 is a view showing the casingdriven, the casing being shown in section, and the drive-shaft, collars, and shoe shown in elevation.

Fig. 3 is a section on the line 33 of Fig. 1, looking in the direction of the arrows adjacent to the line,

Fig. 4 is a sectional view through the driving cap, U

Fig. 5 is a top plan view of the same,

Fig. 6 is a vertical section of the interlocking nut of the drive-shaft,

7 is a top plan view of the same,

Flg. 8 is a partial side view of the shoe or tip, and A Fig. 9 is a top plan view of the same.

The apparatus embodied in this invention, as shown in the drawings, consists of the following 1. A drive-shaft 10, consisting preferably of a wrought-iron or steel pipe, in sections of convenient length. The couplings for these sections to consist of a threaded metal sleeve with a polygonal hole 11.

2. A shoe orv tip 9, with a conical or other sharp point, and with a cylindrical stem 14, of such diameter as to fit easily into the drive-shaft, which normall passes over this stem and rests upon the ase of the shoe. This shoe and stem may consist of metal, concrete, a combination of metal and concrete, or other suitable material. The diameter of the base of this shoe to be slightly larger than that of the outermost casing section, 1.

3. The cylindrical casing sections. These casings to consist of iron or steel plate, or other suitable material. The number of sections for any particular case depends upon the lengtli fixed for these and the depth of penetration required. The drawing shows six, 1 to 6 inclusive. At the top of each of these cylinders, except the outermost one, there is a lug 8, about the outer circumference, and at the bottom of each of them, except the inside one, there is a lug 7, about the inner circumference. The diameter to the outside of the lug 8, on any cylinder, is the same as the diameter to the inside of the lug 7 on the adjacent outside cylinder, and the diameters of these cylinders are such. as

- just to permit the free vertical movement of the cylinders with respect to each other, until the top lug of one comes into contact with the bottom lug of the adjacent outside one. The inside diameter of the innermost cylinder is such as to pass freely over the special fitting on the lower end of the driveshaft. These cylinders are of varying length, as shown, decreasing in regular amounts from the outside one to the inside. A collar 29, is attached to the-outer circumference of the outside cylinder. The cylinders may consist of solid late, or may have perf rations in them i required in special circumstances. 7 4-. The apparatus controlling the motion of the cylinders with respect to the drive- .shaft and shoe, consisting of the collars 21 to 26 inclusive; thebolts or bars 27 and the 'pins 28. The collars, except 26, consist of thick metal rings of constant inside diam-' idly connected to the drive-shaft, by means of screw threads or otherwise, and is so placed as to be in, or nearly in, contact with the top of the innermost cylinder when this rests upon the base of the shoe. This collar is so designed as to provide four suitable holes, at 90 with each other, and through these holes pass the bolts or bars 27, the head of the bolts being below the fitting. These bolts pass through holes provided in the collars. Holes are provided through the bolts just above the position fixed for the top of each collar, for the insertion of pins of a suitable diameter. The position of each collar, when the apparatus is assembled, is determined by the length of the corresponding section of casing, and the lengths of adjacent sections are made to differ by such an amount that there will be a clear space between consecutive collars, permitting the pins above each collar to be placed with ease. The pins are so designed as to be the weakest structural element of the apparatus. That is, the pins will fail in shear under a stress which is insufiicient todamage or distort-the bolt 27, the collars, or the. lugs about the casing sections, when these "latter are in position to limit the movement of one "section with respect to another.

5. Kttached by screw threads 13 to the .bottom f the'drive-shaft, there is a special metal fit ing 12 designed so as to distribute over a larger areathe percussion transmitted to the shoe by the drive-shaft under the impact of the pile-driving. hammer. This fitting 12 and the stem 14 of the shoe, are

so designed as to afford a means of locking the shoe to the drive-shaft, and withdrawing the same, together with the casing. The

. details of this design are shown in Fi s. 6,

7, 8, and 9. In Fig. *8 the maximum iameter of the stem is slightly smaller than the inside diameter of the drive-shaft. This diameter. is decreased over a section'of-the ting 12 is offset so as to provide a shoulder for the drive-shaft to rest upon, and the inside'diameter of this shoulder is equal to that of thesdriveshaft. The depth of this shoulder is made slightly less than the width of the circumferential groove around the stem 14, and on the inside surface there are provided four vertical ribs at 90 with re-- spect to each other the full depth of the shoulder, and of a radial height. equal to that of the depth of the grooves-16 and 19 on the stem 14. Y Consequently, when the ribs on thefitting 12 are turned to register lock the drive-shaft ,to the shoe, to permit withdrawing the latter, the drive-shaft is lifted slightly 'until the bottomof the fitting 12'is just above the top of the lower portion 18, Fig. 9, of the stem. A slight turn of the drive-shaft places the ribs 15 of the fitting 12 in the circumferential, groove on the stem 14, and out of. line with the vertical grooves 16. Any further lifting brings the top-of these ribs into contact with the top shoulder formed by the circumferential groove, and permits the shoe to be withdrawn.

In constructing a cast-in-place concrete pile by means of my invention, the method and the action of the apparatus is as follows The apparatus is first assembled upon the shoe in place in the manner shown in Fig. 1; the 'driving cap 30, Figs. 4 and 5, 1s placed' on the drive-shaft and in the leads of the'Ipile-driver. Thiscap 30 has an annular'groove 31 on its under face, for receiving the outer end of the driving shaft 10,

tion by the collar above it, this section (andv obviously, all of those inside it) 'follow down into the hole with the shoe, all the while resting upon the base of the shoe as shown inthe assembly, Fig. 1. The travel of the outermost section is stopped when the collar 29 comes into contact with the earth or other obstacle provided for the purpose, the resistanceoffered by the collar to further P'travel being sufficient to shear the pins 28 These pins being above the collar '21. sheared, the collar 21 comes to rest upon the top of section 1. The remainder of the collars and sections continue to follow the shoe as it penetrates, passing through the now stationary section 1, until such time as the lug 8 on section 2 comes into contact with lug 7 on section 1. The resistance offered by the lugs to further travel of section 2 is such as to shear the pins above the collar 22 and section 2 comes to rest .with collar 22 at rest upon its top. Section 3 then be comes the outside sectlon in motion, and the above described process is continued. until all the sections are extended and the desired penetration accomplished. It is to be observed that during the entire process of driving, the maximum surface developing skinfriction at any one time is that of one section of casing, since only one of these at a time is both in motion and exposed to the pressure of the penetrated material. Also,- since the hole immediately ahead of this section is of greater diameter than the easing, there will be very little resistance to the travel of this section. v i

The collars, as they come to rest upon the top of their respective sections, continue to perform important functions. They serve as a rigid guide and support for the 'drive' shaft, insuring the efliciency of this member in transmitting the blow of the hammer to the shoe, and insure the correct alinement of the hole. They also serve as supports and reinforcement for the casing sections against the pressure exerted b the penetrated material, during the perio of driving, when this is most needed. They ma also continue in this capacity during the lling of the hole with concrete, as hereinafter mentioned.

Generally, it is desired to leave the casings in the ground, and these may be considered as adequate to resist the pressures against them without the reinforcement afforded by the collars, during the interval between the removal of the collars and the filling of the hole with concrete. In this case, the desired penetration having been accomplished, the

drive-shaftis lifted out, bringing up with'it the collars, which are picked up in order by the fixed collar'26, beginning at the bottom. The hole is then filled with concrete, or other material suitable for the purpose.

I; the material penetrated is such that there would be danger of the collapse of the casing upon the removal of the reinforcing collars, the driving cap may be released and as many sections of the driving shaft as convenient, may' be removed, and concrete poured down the hollow driving shaft, withdrawing this and the collars as the concrete rises in the hole. I

When, for any reason, at any period of driving, it is desired to withdraw the shoe and the cylinders, this may be done by locking the drive-shaft to the shoe, as previously described, and withdrawing the drive-shaft.

The shoe being-of greater diameter than an of the casing cylinders, and concentric wit of the hole and the outside of the casing sections, these sectionsshall be perforated in such manner as to permit the concrete, when poured into the casin to flow out in such quantity as to fill said annular space.

Should the resistance of the penetrated material to the travel of any sections be such' as to shear the pins 27 before said sections have traveled their allotted distance, they will ultimately be extended in full, if the shoe is driven to such depth as would normally accomplish this. The innermost section must travel with the shoe, because of the collar above it (26) being rigidly attached to the drive-shaft. As this section descends, if there are any intermediate sections which are not fully extended, they will be forced into their proper position by virtue of the pull exerted upon their lugs, said pull being primarily transmitted by the upper lug of the innermost section.

I claim 2- 1. A device of the character specified, comprising a drive-shaft, a pointed shoe, a series of interlocking, telescopic, cylindrical casing sections of varying diameter, ar-

ranged one within the other around the drive-shaft and normally resting upon the base of the shoe, a series of collars of varying outside diameter passing over the drive: shaft and resting along their outer edges upon the tops of the respective sections, and a frangible connection between the driveshaft and each of the collars.

2. A device of the character specified, comprising a drive shaft, a series ofinterlocking telescopic casing. sections of varying diameter arrangedone within the other around the drive shaft, a, collar for each section passing over the drive shaft and engaging the adjacent section, and a frangible connection between the drive shaft and each of the collars, and a driving shoe detachably connected with the lower end of the shaft upon whose upper surfaces the sec- 1 tions rest during driving.

3. A device of the character specified, 120.

ing shaft for constraining the section to move with the drive shaft and a frangible connection between the drive shaft and each of the sections and adapted to break under the application of a predetermined degree of force,'and a driving shoe upon whose upper surface the upper sections rest during driving.

5. In a device of the character specified, a series of casing sections arranged 'one within the other, a driving shaft, the driving shaft for constraining the section to move with the drive shaft and a frangible connection between the each of the sections and adapted to break under the application of a predetermined degree of force.

6. In a device of the character specified, a series of casing sections arranged one within the'other, a driving shaft, a frangible connection between the drive shaft and each of the sections, said connection being adapted to yield on the application of a. predetermined degree of force for the purpose specified, a driving shoe at the lower end of the driving shaft upon which the lower ends of the section rest, and a detach-' able connection between the shoe and the sllliafft releasable at the upper end of the s a t.

7. A device of the character specified cornprising a drive shaft and a series of interlocking telescoping sections, a rigid connection between the drive shaft and themnermost section for constraining the; section to move with the driving shaft,'and a frangible connection betweenthe driving shaft and the remainin sections forconstraining them to move withthe driving shaft and drive shaft andadapted to break under a predetermined force to release the sections in succession.

8. A deviceof the character specified comprising a driving shaft and a series of interlocking telescoping sections, a rigid connection between the driving shaft and the innermost section for constraining the section to move with the driving shaft, and a frangible connection between the driving shaft and the remaining sections for constraining them to move with the driving shaft and adapted to break under a predetermined force to release the sections in succession, said first named connection comprising a collar rigid with the shaft and engaging over the top of the innermost section.

9. A device of the character specified comprising a driving shaft and a series of interlocking telescoping sections, a rigid connection between the drive shaft and the innermost section for constraining the section to move with the driving shaft, and a frangible connection between the. driving shaft and the remaining sections for constrainin them to move the driving shaft and adapte to break under a predetermined force to release the sections in succession, said first named connection comprising a collar rigid with the shaft and engaging over the top of the innermost section, the frangible connection comprising a series of collars, each extending outwardly'to engage ,a section,

rods extending from the first named collar through the other collars and pins extending transversely of the rods above the collars. I SHEPARD M. COTTEN. Witnesses: I

w. BANUMA, B. M. A'rwoon. 

